We examined the effect of peripheral eletrical stimulation on intelligence and memory in patients with dementia. It was hypothesized that in the early stage of the illness, electrical stimulation could activate the affected cortical regions by stimulating the neurotransmitter systems projecting to these areas. The results reveal that electrical stimulation of the SeiMei point improves the intelligence and short.term memory in these patients. Moreover, the effect is more significant in patients in early stage than in those in late stage. Furthermore, the three parameters of the dementia diagnostic system, which is using miosis by light reflex studied by our research group, are also improved after the electrical stimulation.